A process for producing a diolefin polymer or copolymer and a rubber composition containing such a diolefin polymer or copolymer

Abstract: A process for producing a diolefin polymer or copolymer, comprising the steps of polymerizing 55-100 wt% of a conjugated diolefin with 0-45 wt% of an aromatic vinyl compound as monomers in a hydrocarbon as a solvent, by using initiators: a reaction product [a1] between at least one secondary amine compound (A) and an organic lithium compound and/or a lithium amide compound [a2] of the at least one secondary amine compound (A) as well as a reaction product [b1] between at least one alcohol (B) and an organic lithium compound and/or a lithium alkoxide compound of the at least one alcohol (B). A rubber composition containing not less than 30 wt% of such a diolefin polymer or copolymer with respect to an entire rubber component is also disclosed. This rubber composition exhibits excellent abrasion resistance, high tensile strength, steering stability and low rolling resistance, and is suitable for tires, particularly, as treads of low fuel consumption tires.

Description: The present invention relates to a process for producing a polymer or copolymer to be appropriately used for tire treads and having excellent abrasion resistance, high tensile strength, steering stability and low rolling resistance. More particularly, the invention relates to a process for producing a conjugated diolefin polymer or copolymer by polymerizing a conjugated diolefin or copolymerizing a conjugated diolefin and an aromatic vinyl compound by using a specific initiator in a relatively short time and optionally effectively modifying polymerization- or copolymerization-active terminals with a tin compound, a silicon compound and/or an organic compound containing a hetero atom, said specific initiator being a reaction product between a secondary amine compound and an organic lithium compound and/or a lithium amide compound, a reaction product between a specific alcohol and an organic lithium compound and/or a specific lithium alkoxide compound. The invention also relates to a rubber composition containing such a polymer or copolymer and suitable for use in tire treads. With increased demand for low fuel consumption in automobiles, conjugated diolefin polymers or copolymers having all of excellent abrasion resistance, low rolling resistance, steering stability and high tensile strength have been recently requested as rubber materials, particularly for tire treads. In order to reduce rolling resistance of a tire, energy loss of vulcanized rubber has to be decreased. As indices for evaluating the vulcanized rubber, rebound resilience at 50°C-80°C, tan δ at 50°C-80°C, Goodrich heat generation, etc. have been employed. Raw rubber materials having larger rebound resilience at 50-80°C, smaller tan δ at 50°C-80°C or smaller Goodrich heat generation are preferable. Up to now, styrene-butadiene copolymers having various structures polymerized with use of organic lithium initiators and styrene-butadiene copolymers having terminals of the copolymers modified with functional groups have been proposed as raw rubber materials having large rebound resilience. For example, there are styrene-butadiene copolymers having their terminals modified or coupled with tin compounds as well as styrene-butadiene copolymers having their terminals modified with a nitrogen-containing compound such as an isocyanate compound, an oxazolidinon compound, or a dialkylaminobenzophenon compound. However, a polymer or copolymer obtained by using an organic lithium initiator has a smaller amount of functional groups introduced thereinto through modification of the terminals of the polymer or copolymer. Accordingly, it was difficult to realize the demand for improving the above physical properties such as abrasion resistance and reduced rolling resistance. Formerly, two processes were known to increase the amount of the functional groups introduced. That is, the amount of the functional groups introduced is increased (1) by effecting polymerization with use of a lithium amide initiator and modifying or coupling the terminals of the resulting polymer or copolymer (Japanese patent application Laid-open No. 59-38,209 and Japanese patent publication No. 5-1,298), or (2) by preliminarily reacting an organic lithium initiator with a vinyl compound having a low number of functional groups, and effecting the polymerization with use of the resulting reaction product, while modifying the terminals of the polymer or copolymer (Japanese patent publication No. 5-1298). However, it is reported in these publications that a longer time is required to obtain the polymer or copolymer as compared with the case where the polymerization is effected with the organic lithium initiator alone. Further, reactivity of the terminals of the polymer or copolymer drops, so that the modifying reaction efficiency is unfavourably low. Thus, it has been difficult to increase the introduced amount of the functional groups. On the other hand, in the case that a diolefin or an olefin which is substituted with a polar group such as an ester, a nitrile or an aryl group is polymerized (copolymerized) with an alkaline metal amide compound, it is known that the yield of the polymer or copolymer is increased through the addition of alkaline metal alkoxide (Japanese patent application Laid-open No. 54-100,484). However, since this process also needs a long time to obtain the polymer or copolymer in the case of the polymerization of the conjugated diolefin and/or aromatic vinyl compound, the above-mentioned problem of the prior art could not be solved by this process, either. That is, the speed of the polymerization of the conjugated diolefin and/or the aromatic vinyl compound with use of the lithium amide initiator is small, and the reactivity of active terminals of the polymer or copolymer is small. Tires are broadly classified into (1) low fuel consumption tires having low rolling resistance, (2) large size tires to be used in trucks or buses having good abrasion resistance, and (3) high performance tires having improved steering stability and high tensile strength at high speeds, depending upon uses thereof. As to low fuel consumption tires, the tires are improved to some extent by the above technical idea. As to the high performance tires, trials have been made to increase an amount of an extender oil or to add a special liquid rubber or the like. However, these trials both adversely affect the rolling resistance and abrasion resistance, so that it is difficult to simultaneously satisfy all of the performances mentioned above. For large tires, although high cis-polybutadiene has been conventionally mainly used, it is unfavorably difficult to modify or couple the terminals of the polymer. That is, a conjugated diolefin polymer or copolymer applicable to all of the above uses has not been discovered. It is therefore an object of the present invention to provide a process for producing a polymer or copolymer by the step of polymerizing a conjugated diolefin alone or copolymerizing such a conjugated diolefin and an aromatic vinyl compound, which can shorten the polymerization or copolymerization time. The producing process of the invention may further comprise the step of modifying or coupling the resulting polymer or copolymer, which improves modifying or coupling reactivity. It is another object of the present invention to provide a rubber composition having excellent abrasion resistance, high tensile strength, low rolling resistance, and steering stability improved and composed of the polymer or copolymer produced by the invention process. The present invention provides a process for producing a conjugated diolefin polymer or copolymer, comprising the step of polymerizing 55-100% by weight of a conjugated diolefin with 0-45% by weight of an aromatic vinyl compound as monomers by using initiators [a1] and/or [a2] as well as initiators [b1] and/or [b2] in a hydrocarbon solvent, in the presence of an ether compound or a tertiary amine if necessary, wherein [a1] is a reaction product between at least one secondary amine compound (A) selected from compounds represented by the following formulae (a1-1), (a1-2) and (a1-3) and an organic lithium compound, a molar ratio between said at least one secondary amine compound (A) and said organic lithium compound being 1:0.2-5; (a1-1) is in which R 1 and R 2 are the same or different, and denote a group selected from H- or an alkyl group having 1-20 carbon atoms or an aryl group having 6-20 carbon atoms; (a1-2) is in which R 3 and R 4 are the same or different and denote an alkylene group having 1-3 carbon atoms, X is a group selected from -CH 2 -, -O- or -NH-, R 5 is H- or an alkyl group having 1-5 carbon atoms, and k is an integer of 1-4; (a1-3) is 5-benzyloxyindole, 3-azaspiro[5,5]undecane, 3-azabicyclo[3,2,2]nonane, and carbazole; [a2] is a lithium amide compound obtained by substituting Li for H in a >NH group of said secondary amine compound (A); [b1] is a reaction product between at least one alcohol (B) selected from compounds represented by the following formulae (b1-1), (b1-2), (b1-3), (b1-4) and (b1-5) and an organic lithium compound, a molar ratio between said at least one alcohol (B) and said organic lithium compound being 1:0.8-5; (b1-1) is in which R 6 , R 7 , and R 8 are the same or different, and denote H- or an alkyl group having 1-5 carbon atoms, and m is an integer of 1-3: (b1-2) is in which R 9 , R 10 , R 11 , R 12 , and R 13 are the same or different, and denote H- or an alkyl group having 1-5 carbon atoms, and n is an integer of 1-3; (b1-3) is R 14 p N[(CH 2 ) q -OH] 3-p in which R 14 is an alkyl group having 1-20 carbon atoms or an aryl group having 6-20 carbon atoms, p is an integer of 0-2, and q is an integer of 1-3; (b1-4) is in which R 15 and R 16 are the same or different, and denote an alkylene group having 1-3 carbon atoms, Y is a group selected from -CH 2 -, -O-, -NH- and =N-(CH 2 ) s OH, r is an integer of 1-3, and s is an integer of 1-3; (b1-5) is in which R 17 and R 18 are the same or different, and denote H- or an alkylene group having 1-5 carbon atoms, and t is an integer of 1-3: [b 2 ] is a lithium alkoxide compound obtained by substituting Li for H of the -OH in the alcohol (B); and wherein the content of vinyl bonds in the conjugated diolefin portion of the said polymer or copolymer is 15-90%. The following are preferred as specific embodiments of the producing process of the present invention. (1) The producing process further comprises the step of, after the polymerization, modifying or coupling polymerization- or copolymerization-active terminals with use of one or more compounds, as a modifier, selected from the following compounds a o to k o , within a time period during which said polymerization- or copolymerization-active terminals remain: "a o " an isocyanate compound and/or an isothiocyanate compound "b o " a derivative of an isocyanuric acid and/or a thiocarbonyl-containing compound having a chemical structure corresponding to that of said isocyanuric acid derivative "c o " a urea compound "d o " an amide compound and/or an imide compound "e o " an N-alkyl-substituted oxazolidinon compound "f o " a pyridyl-substituted ketone compound and/or a pyridyl-substituted vinyl compound "g o " a lactam compound "h o " a silicon compound "i o " an ester compound "j o " a ketone compound "k o " a tin compound The following (2) through (15) are preferred embodiments of the above preferred producing process (1) of the present invention. (2) The producing process set forth above, wherein before said modifier is added, 0.5-500 mol of 1,3-butadiene per 1 gram equivalent of lithium atom is added, and then the polymerization or copolymerization is further effected. (3) The producing process set forth above, wherein the molar ratio between said lithium compound of said [a1] or said lithium amide compound of said [a2] and said organic lithium compound of said [b1] or said lithium alkoxide compound of [b2] is 1:0.01-2.0. (4) The producing process set forth above, wherein said [a1] is a reaction product between the secondary amine compound of the formula (a1-1) and said organic lithium compound, and said [a2] is a lithium amide compound obtained by substituting Li for H in -NH groups of the compound of said (a1-1). (5) The producing process set forth above, wherein said [b1] is a reaction product between the compound of said (b1-1) and/or the compound of said (b1-3) and said organic lithium compound, and [b2] is a lithium alkoxide compound obtained by substituting Li for H in -OH groups of the compound of said (b1-1) and/or the compound of said (b1-3). (6) The producing process set force above, wherein said organic lithium compound is an alkyl lithium having 3-10 carbon atoms. (7) The producing process set forth above, wherein said hydrocarbon solvent is a cycloaliphatic hydrocarbon and/or an alphatic hydrocarbon having 3-10 carbon atoms. (8) The producing process set forth above, wherein said conjugated diolefin is 1,3-butadiene and/or isoprene, and said aromatic vinyl compound is styrene. (9) The producing process set forth above, wherein said [a1] is a reaction product between di-n-butylamine and said organic lithium compound, and [a2] is lithium di-n-butyl amide. (10) The producing process set forth above, wherein said [b1] is a reaction product between N,N-diethyl ethanolamine and/or tetrahydrofurfuryl alcohol and said organic lithium compound, and [b2] is N,N-diethylamino lithium ethoxide and/or tetrahydrofurfuryl lithium alkoxide. (11) The producing process set forth above, wherein said modifier is at least one compound selected from the isocyanate compound (a o ), the silicon compound (h o ) and the tin compound (k o ). (12) The producing process set forth above, wherein said modifier is at least one tin compound (k o ) in an amount of 0.05-5 gram equivalents per one gram equivalent of lithium atoms. (13) The producing process set forth above, wherein a rate of the modified or coupled polymer or copolymer to the entire polymer or copolymer is not less than 20% by weight based on the total polymer or the diolefin portion of said copolymer. (14) The producing process set forth above, wherein a content of vinyl groups in said diolefin polymer or copolymer is 15-40% by weight based on said polymer or diolefin portion of said copolymer. (15) The producing process set forth above, wherein the polymerization is effected by using, as an initiator, said [a1] being a reaction product between di-n-butyl amine and an organic lithium compound and/or [a2] being lithium di-n-butylamide and said [b1] being a reaction product between N,N-diethyl ethanolamine and/or tetrahydrofurfuryl alcohol and the organic lithium compound and/or [b2] being N,N-diethylaminolithium ethoxide and/or tetrahydrofurfuryl lithium alkoxide; further polymerization is effected after 0.5-500 mol of 1,3-butadiene is added to the resulting polymer or copolymer per 1 gram equivalent of lithium; and the resulting polymer or copolymer is modified or coupled by adding at least modifier selected from polymeric type diphenylmethane diisocyanate, dimethyl adipate, 4,4'-bis(dimethylamino)benzophenon, tin tetrachloride, silicon tetrachloride, and tin dichlorodibutyl, thereby making the rate of the modified or coupled polymer or copolymer not less than 20% by weight relative to the entire polymer or copolymer. The present invention also provides a rubber composition containing not less than 30% by weight of a diolefin polymer or copolymer with respect to an entire rubber component, said diolefin polymer or copolymer being obtained by the following steps: (1) polymerizing 55-100% by weight of a conjugated diolefin with 0-45% by weight of an aromatic vinyl compound as monomers by using initiators [a1] and/or [a2] as well as initiators [b1] and/or [b2], wherein each of [a1], [a2], [b1] and [b2] is as defined above; (2) after the polymerization, modifying or coupling polymerization- or copolymerization-active terminals with use of one or more compounds, as a modifier, selected from compounds (a 0 ) through (k 0 ), within a time period during which said active terminals remain, wherein each of said compounds (a 0 ) through (k 0 ) is as defined above. The following rubber composition is preferred as a specific embodiment of the rubber composition of the present invention, which is produced by the process comprising the steps of: (i) copolymerizing 55-90% by weight of said conjugated diolefin and 45-10% by weight of said aromatic vinyl compound as the monomers; and (ii) after the polymerization, modifying or coupling active terminals of the resulting copolymer with use of one or more compounds, as a modifier, selected from said compounds (a o ), (h o ) and (k o ) within a time period during which said active terminals remain. The process of the invention for the production of the conjugated diolefin polymer or the conjugated diolefin-aromatic vinyl compound copolymer is characterized in that the conjugated diolefin alone or the conjugated diolefin and the aromatic vinyl compound are solution-polymerized or solution-copolymerized in a solvent of a hydrocarbon with use of a specific initiator, in the presence of an ether or a tertiary amine compound if necessary, said specific initiator being a reaction product between a secondary amine compound and an organic lithium compound and/or a lithium amide compound as well as a reaction product between a specific alcohol and an organic lithium compound and/or a specific lithium alkoxide compound. Terminals of the resulting polymer or copolymer may be modified or coupled. As the conjugated diolefin compound, for example, 1,3-butadiene and isoprene may be recited, and 1,3-butadiene is preferred among them. As the aromatic vinyl compound, for example, styrene, vinyltoluene, p-methylstyrene, and α-methylstyrene may be recited, and styrene is preferred among them. The content of bound aromatic vinyl compound is ordinarily 0-50% by weight, more preferably 10-45% by weight. If the content of the bound aromatic vinyl compound exceeds 50% by weight, rebound resilience lowers. On the other hand, the content of the vinyl bonds in the conjugated diolefin portion of the above polymer or copolymer is 15-90%. If the content is less than 15%, it may be difficult to produce the polymer or copolymer aimed at by the present invention in some cases. A vinyl content of 15-40% effectively improves tensile strength, and abrasion resistance and rolling resistance. Particularly, the rolling resistance is conspicuously improved when the content of the vinyl bonds is 30-70%. Further, when the content of the vinyl bonds is 50-90%, the gripping performance and steering stability are effectively improved. As a hydrocarbon solvent, for example, pentane, hexane, heptane, octane, methylcyclopentane, cyclohexane, benzene, and xylene may be recited. As the initiator, a reaction product between a secondary amine compound and an organic lithium compound and/or a lithium amide compound and a reaction product between a specific alcohol and an organic lithium compound and/or a specific lithium alkoxide are used. As the secondary amine compounds corresponding to (a1-1) of the initiators used in the present invention, for example, dimethylamine, diethylamine, dipropylamine, di-n-butylamine, dipentylamine, dihexylamine, dioctylamine, dicyclohexylamine, and N-methylbenzylamine may be recited. As the secondary amine compounds corresponding to (a1-2), for example, morpholine, piperazine, 2,6-dimethylmorpholine, 2,6-dimethylpiperazine, 1-ethylpiperazine, 2-methylpiperazine, 1-benzylpiperazine, piperidine, 3,3-dimethylpiperidine, 2,6-dimethylpiperidine, 1-methyl-4-(methylamino)piperidine, 2,2,6,6-tetramethylpiperidine, 2,5-dimethylpyrrolidine, 2,5-dimethyl-3-pyrrolidine, azetidine, and heptamethylene imine may be recited. As the compounds corresponding to (a1-3), 5-benzyl-oxyindole, 3-azaspiro[5,5]undecan, 3-azabicyclo[3,2,2]nonane, and carbazole are recited. As specific examples of the lithium amide compounds, for example, lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium di-n-butylamide, lithium dipentylamide, lithium dihexylamide, lithium dioctylamide, lithium N-methylbenzylamide, lithium dicyclohexylamide, lithium morpholinoamide, and lithium piperazinoamide may be recited. Each of these lithium amide compounds may be used alone, but each of them may be used together with at least one potassium compound or organic potassium compound disclosed in Japanese patent application Laid-open No. 63-297,410 in an amount of 0.001-0.5 mols per 1 gram equivalent of lithium. As specific examples of the alcohols corresponding to the above (b1-1), for example, tetrahydrofurfuryl alcohol, furfuryl alcohol, 3-methyl-tetrahydrofurfuryl alcohol, 4-ethyl-tetrahydrofurfuryl alcohol, and oligomers of tetrahydrofurfuryl alcohol may be recited. Among them, tetrahydrofurfuryl alcohol is preferred. As specific examples of the compounds corresponding to (b1-2), for example, ethylene glycol monophenylether, and ethylene glycol monobutylether may be recited. As the compounds corresponding to (b1-3), for example, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N,N-diphenylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-butydilethanolamine, N-phenyldiethanolamine, N,N-dimethylpropanolamine, N,N-dibutylpropanolamine, N-methyldipropanolamine, N-ethyldipropanolamine, 1-(2-hydroxyethyl)pyrrolidine, 2-methyl-1-(2-hydroxyethyl)pyrrolidine, 2-methyl-1-(3-hydroxypropyl)pyrrolidine, 1-piperidine ethanol, 2-phenyl-1-piperidine ethanol, 2-ethyl-1-piperidine propanol, N-β-hydroxyethylmorpholine, 2-ethyl-N-β-hydroxyethylmorpholine, 1-piperadine ethanol, 1-piperadine propanol, N,N'-bis(β-hydroxyethyl)-piperadine, and N,N'-bis(γ-hydroxypropyl)piperadine may be recited. Among them, N,N-dimethylethanolamine, N,N-dimethylethanolamine, and 1-piperizine ethanol are preferred. As the compounds corresponding to (b1-4), for example, 2-(β-hydroxyethyl)pyridine, and 2-(γ-hydroxypropyl)-pyridine may be recited. As specific examples of the organic lithium compounds used in the present invention, ethyllithium, propyllithium, n-butyllithium, sec-butyllithium, and t-butyllithium, and hexyllithium may be recited. Among them, n-butyllithium and sec-butyllithium are preferred. Further, each of these organic lithium compounds may be used alone, but each of them may be used together with at least one potassium compound and organic potassium compound disclosed in Japanese patent application Laid-open No. 63-297,410 in an amount of 0.001-0.5 mol per one gram equivalent of lithium. It is necessary that the molar ratio between the secondary amine compound (A) in the above [a1] component and the organic lithium compound is 1:0.2-5. If the molar ratio between the organic lithium compound and the secondary amine compound (A) exceeds 5, tensile strength, abrasion resistance and rolling resistance cannot be improved. On the other hand, if the molar ratio of the organic lithium compound is less than 0.2, the polymerizing speed greatly decreases. The molar ratio between the secondary amine compound (A) and the organic lithium compound is preferably 1:1. Further, it is necessary that the molar ratio between the alcohol (B) in the above [b1] component and the organic lithium compound is 1:0.8-5. If the molar ratio of the organic lithium compound exceeds 5, tensile strength, abrasion resistance and rolling resistance cannot be improved. On the other hand, if the molar ratio of the organic lithium compound to the alcohol (B) is less than 0.8, the polymerizing speed greatly decreases. The molar ratio between the alcohol (B) and the organic lithium compound is preferably 1:1. Furthermore, it is preferable that the molar ratio between the reaction product of the [a1] component and the organic lithium compound or the lithium amide compound [b2] and the reaction product of [b1] component and the organic lithium compound or the lithium alkoxide compound [b2] is 1: 0.01-2.0. Further, when the initiator is prepared from the [a] component {[a1] and/or [a2]} and the [b] component {[b1] and/or [b2]}, it is preferable that 1-100 mols, more preferably 1-50 mols, of 1,3-butadiene is added relative to 1 mol of the [a] component. By so doing, the polymerizating reaction smoothly proceeds. In the present invention, as the specific compound to be used for modifying or coupling active terminals of the resulting polymer or copolymer produced in the present invention within a time period during which said active terminals remain, at least one compound selected from the group consisting of the following (a o ) through (k o ) may be used. (a o )an isocyanate compound and/or an isothiocyanate compound (hereinafter referred to briefly as (a o ) component) (b o )a derivative of an isocyanuric acid and/or a thiocarbonyl-containing compound having a chemical structure corresponding to that of said isocyanuric acid derivative (hereinafter referred to briefly as (b o ) component) (c o )an urea compound (hereinafter referred to briefly as (c o ) component) (d o )an amide compound and/or an imide compound (hereinafter referred to briefly as (d o ) component) (e o )an N-alkyl-substituted oxazolidinon compound (hereinafter referred to briefly as (e o ) component) (f o )a pyridyl-substituted ketone compound and/or a pyridyl-substituted vinyl compound (hereinafter referred to briefly as (f o ) component) (g o )a lactam compound (hereinafter referred to briefly as (g o ) component) (h o )a silicon compound(hereinafter referred to briefly as (h o ) component) (i o )an ester compound(hereinafter referred to briefly as (i o ) component) (j o )a ketone compound(hereinafter referred to briefly as (j o ) component) (k o )a tin compound(hereinafter referred to briefly as (k o ) component) Among these compounds, specific examples of the isocyanate compounds or the isothiocyanate compounds as the (a o ) component include 2,4-trilenedisocyanate, 2,6-trilenediisocyanate, diphenylmethanediisocyanate, polymeric type diphenylmethane diisocyanate (C-MDI), phenylisocyanate, isophorondiisocyanate, hexamethylenediisocyanate, butylisocyanate, 1,3,5-benzentriisocyanate, phenylisothiocyanate, and phenyl-1,4-diisothiocyanate. Specific examples of the derivative of an isocyanuric acid and the thiocarbonyl-containing compound having the chemical structure corresponding to that of said isocyanuric acid derivative which are recited as the (b o ) component include derivatives of carbamic acid, such as methyl carbamate and methyl N,N-diethylcarbamate, isocyanuric acid, and derivatives of isocyanuric acid, such as N,N',N'-trimethylisocyanuric acid. As specific examples of the urea compounds as the (c o ) component, N,N'-dimethyl urea, N,N'-diethyl urea, N,N,N',N'-tetramethyl urea, and N,N-dimethyl-N',N'-diphenyl urea may be recited. As specific examples of the amide compounds and imide compounds as the (d o ) component, for example, amides such as N,N-dimethylformamide, acetoamide, N,N-diethylacetoamide, aminoactetoamide, N,N-dimethyl-N,N'-dimethylaminoacetoamide, N,N-dimethylaminoacetoamide, N,N-ethylaminoacetoamide, N,N-dimethyl-N'-ethylaminoacetoamide, acrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, nicotineamide, isonicotineamide, picorinic acid amide, N,N-dimethylisonicotineamide, succinic acid amide, phthalamide, N,N,N',N'-tetramethylphthalamide, oxamide, N,N,N',N'-tetramethyloxamide, 2-furancarbonic acid amide, xynoline-2-carbonic acid amide, and N-ethyl-N-methyl-xynoline carbonic acid amide, and imides such as succinic acid imide, N-methylsuccinic imide, maleimide, N-methylmaleimide, phthalimide, and N-methylphthalimide may be recited. As specific examples of the N-alkyl substituted oxazolidinone compounds as the (e o ) component, for example, 1,3-diethyl-2-imidazolidinon, 1,3-dimethyl-2-imidazolidinon, 1,1-dipropyl-2-imidazolidinon, 1-methyl-3-ethyl-2-imidazolidinon, 1-methyl-3-propyl-2-imidazolidinon, 1-methyl-3-butyl-2-imidazolidinon, 1-methyl-3-(2-methoxyethyl)-2-imidazolidinon, 1-methyl-3-(2-ethoxyethyl)-2-imidazolidinon, and 1,3-di-(2-ethoxyethyl)-2-imidazolidinon may be recited. As specific examples of the pyridyl-substituted ketone compounds as the (f o ) component, for example, methyl-2-pyridyl ketone, methyl-4-pyridylketone, propyl-2-pyridylketone, di-4-pyridylketone, propyl-3-pyridylketone, 2-benzoylpyridine, 2-vinylpyridine, and 4-vinylpyridine may be recited. As specific examples of the lactam compounds as the (g o ) component, for example, N-methyl-2-pyrrolidone, 2-piperidon, N-methyl-2-piperidone, 2-quinoline, and N-methyl-quinolone may be recited. The use amount of one or more of these compounds as the (g o ) component is ordinarily 0.2-10 equivalents, more preferably 0.5-5.0 equivalents, based on the functional group, i.e., on isocyanate group, the isothiocyanate group, the carbonyl group, the vinyl group, or the aldehyde group per one atomic equivalent of alkaline metal atoms. If the use amount is less than 0.2 equivalents, rebound resilience and low heat generation property of the vulcanized rubber become poorer, whereas if the use amount is more than 10 equivalents, an amount of a non-reacted material increases to generate offensive odor, raise the vulcanizing speed or deteriorate the rebound resilience and the low heat generation property of the vulcanizate. As specific examples of the silicon compounds as the (h o ) component, for example, dibutyldichlorosilicon, methyltrichlorosilicon, methyldichlorosilicon, tetrachlorosilicon, and triphenoxymethylsilane may be recited. The addition amount of one or more of these compounds may be in an amount of 0.05-5 equivalents, more preferably 0.1-1.5 equivalents, based on the halogen atoms or the phenoxy group with respect to one atomic equivalent of alkaline metal atoms. As specific examples of the ester compounds as the (i o ) component, for example, diethyl adipate, diethyl malonate, diethyl phthalate, diethyl glutarate and diethyl maleate may be recited. The addition amount of one or more of these compounds may be 0.05-5 equivalents per one atomic equivalent of alkaline metal atoms. As specific examples of the ketone compounds as the (j o ) component, for example, N-methyl-2-pyrrolidone, N,N-dimethylformamide, nicotineamide, and 4,4'-bis(diethylamino)benzophenone may be recited. The addition amount of one or more of these compounds may be 0.05-5 equivalent per one atomic equivalents of alkaline metal atoms. As specific examples of the tin compounds as the (k o ) component, for example, tin tetrachloride, tin tetraboromide, tin trichlorobutyl, tin trichloromethyl, tin trichlorooctyl, tin dibromodimetyl, tin dichlorodimethyl, tin dichlorodioctyl, tin dichloro dioctyl, 1,2-bis(trichlorostanyl)ethane, 1,2-bis(methyldichlorostanyl)ethane, 1,4-bis(trichlorostanyl)butane, 1,4-bis(methyldichlorostanyl)butane, ethyl tin tristearate, butyl tin trisoctanoate, butyl tin trisstearate, butyl tin trislaurate, dibutyl tin bisoctanoate, dibutyl tin bisstearate, and dibutyl tin bislaurate may be recited. The addition amount may be in a range of 0.05-5 equivalents per one atomic equivalent of lithium atoms. Each of the compounds to be reacted with the polymer or copolymer produced may be used singly or in combination with one or more kinds of the other. In order to enhance both reactivity of polymerization site and reactivity of these compounds towards the active terminals of polymer or copolymer, it is preferable that after 1,3-butadiene is further added to the polymerization system in amount of 0.5-500 mols, more preferably 1-200 mols, per one gram atomic equivalent of lithium atoms, the modifying or coupling reaction is effected for the active terminals. Among the above-recited compounds, the use of the tin compounds gives excellent improvement in abrasion resistance and rolling resistance aimed at by the present invention, which affords a polymer or copolymer to be suitably used for low fuel consumption tires or large size tires. In addition, the above compounds among the (a o ) through (j o ) components are preferred for high performance tires requiring steering stability and high tensile strength, and an extender oil and/or a liquid rubber may be added to the polymers or copolymers modified or coupled with these compounds. It is preferable that the polymer or copolymer according to the present invention contains not less than 20% by weight of the polymer or copolymer having terminals modified or coupled. If the content of the polymer or copolymer having the terminals modified or coupled is less than 20% by weight, tensile strength and rebound resilience become unfavourably poorer. The polymerization or copolymerization reaction and the modifying reaction or coupling reaction are ordinarily effected in a range of 0-120°C. These reactions may be effected under a temperature-elevated or heated condition. The polymerization or copolymerization system may be a batch polymerization or copolymerization or a continuous polymerization or copolymerization. As to the microstructure of the conjugated diolefin polymer or the conjugated diolefin portion of the copolymer, the content of vinyl bonds may be varied by adding an ether such as tetrahydrofuran, diethylether, dimethoxybenzene, dimethoxyethane, ethylene glycol dibutylether, or tertiary amine compounds such as triethylamine, pyridine, N,N,N',N'-tetramethylethylenediamine, and/or dipiperidinoethane to the polymerization or copolymerization system. Further, it is preferable that the Mooney viscosity (ML 1+4 ,100°C) of the polymer or copolymer of the present invention is in a range of 20-200. If the Mooney viscosity is less than 20, tensile strength and rebound resilience become unfavourably poorer. On the other hand, if the Mooney viscosity is more than 100, processability becomes unfavourably poorer. In the latter case, however, the Mooney viscosity may be lowered to not more than 100 by adding an extender oil such as an aromatic process oil or a naphthenic process oil, which enables the polymer or copolymer to be used without trouble in processing. In this connection, note is to be taken that if an extender oil is added to the polymer or copolymer modified or coupled with the tin compound, tin-carbon bonds are unfavourably readily broken under an acidic condition. The rubber composition according to the present invention is composed of the above-mentioned polymer or copolymer as an indispensable component, and may include other rubber component in the form of a blend. Preferably, one or more kinds of rubbers selected from natural rubber, high-cis polybutadiene polymerized by using nickel, cobalt, titanium or neodymium as a catalyst, emulsion-polymerized styrene-butadiene copolymer, solution-polymerized styrene-butadiene copolymer which has no tertiary amine groups at terminals of the copolymer with a content of bound styrene of 10-40% by weight and a content of vinyl bonds of 15-80% by weight in the conjugated diolefine portion, low-cis polybutadiene, and ethylene-propylenediene terpolymer are blended as other rubber component or components. The rubber composition is obtained by further compounding a process oil such as an aromatic process oil or naphthenic process oil, other various compounding agents and a vulcanizer to the resulting mixture depending upon necessity. The polymer or copolymer obtained by the present invention is ordinarily contained in the rubber composition in an amount of 30% by weight or more relative to 100 parts by weight of the rubber composition. If the percentage of the polymer or copolymer is less than 30% by weight, a rubber composition having excellent abrasion resistance, rolling resistance, steering stability and high tensile strength as aimed at by the present invention may not be obtained. The present invention will be further explained with reference to specific examples given below. Various measurements made in the following experiments were effected by the following methods. (1) Mooney viscosity: Mooney viscosity was measured at a temperature of 100°C after preheating for 1 minute and driving a rotor for 4 minutes according to Japanese Industrial Standard (abbreviated "JIS") K6300. (2) Microstructure of polymer or copolymer: The microstructure of the polymer or copolymer was determined by an infrared absorption spectrum method (Morero's method). (3) Content of bound styrene: The content of bound styrene was determined based on a calibration curve formed by utilizing the infrared absorption spectrum method. (4) Weight-average molecular weight, Number-average molecular weight and molecular weight distribution: The weight-average molecular weight, the number-average molecular weight and the molecular weight distribution were determined on the basis of polystyrene by gel permeation chromatography (GPC) with a Chromatography machine Type 244 manufactured by Water Co. Ltd. (5) Coupling efficiency: The coupling efficiency was determined from a change in molecular weight between before and after the modifier was added. The coupling efficiency denotes the rate of the polymer or copolymer having the terminals modified or coupled, relative to the entire polymer or copolymer. (6) Physical properties of vulcanizate: Physical properties of the vulcanizate were evaluated in various measurements with respect to the vulcanizate obtained by kneading a raw rubber and other additives in a 250 ccm laboratory plastmill according to a compounding recipe in Table 1, and vulcanizing the mixture at 145°C for a given time period. (7) Tensile strength: Tensile strength was measured according to JIS K6301. (8) Lambourn abrasion index: Abraded amount was measured by using a Lambourn abrasion tester at a slip rate of 25%. Results are shown by index. The temperature was at room temperature. The greater the index, the better is the abrasion resistance. (9) Tan δ at 50°C and tan δ at 0°C: Tan δ at 50°C was measured by using a dynamic spectrometer manufactured by Reometrics Co., Ltd. in U.S.A. under the conditions that tensile dynamic strain was 1%, frequency was 10 Hz, and temperature was 50°C. Results are shown by index. The greater the figure, the better or smaller is the rolling resistance. Further, tan δ at 0°C was measured by using the same machine under the conditions that tensile dynamic strain was 0.1%, frequency was 10 Hz, and temperature was 0°C. Results are shown by index. The greater the figure, the better or greater is the wet skid resistance. (10) Dry skid performance: Dry skid performance was measured by using a portable skid tester manufactured by Road Research Co., Ltd. in England. An asphalt road was used for testing. Results are shown by index. The greater the figure, the greater is the gripping performance and the better is the steering stability. Example 1 Into a 300 ml pressure-proof bottle were added 25 g of cyclohexane, 1.69 mmols of lithium diethylaminoethoxide as a [b2] component, 3.4 mmols of di-n-butylamine as a [a1] component, and 3.4 mmols of n-butyllithium in this order, which were reacted at 27°C for 15 minutes. Then, 37 mmols of 1,3-butadiene was added to the reaction mixture, which was reacted for another 15 minutes to obtain a solution of an initiator. Next, as shown in Table 2, 2400 g of cyclohexane, 240 g of styrene, 324 g of 1,3-butadiene, and 1.68 g of tetrahydrofuran were charged into a reactor vessel having an inner volume of 5 liters purged by nitrogen. After the mixture was set to a polymerization-initiating temperature of 60°C, the entire initiator solution prepared above was added to the monomer solution to effect the copolymerization. When the conversion rate reached 100%, 36 g of 1,3-butadiene was added to convert terminals of the copolymer to lithium butadienyl. Then, 1.26 mmol silicon tetrachloride was added to the reaction mixture, which was reacted for 10 minutes. Thereafter, 2,6-di-tertiary butyl-p-cresol was added to the copolymer solution, to which 37.5 parts by weight of a highly aromatic extender oil (AROMA manufactured by Japan Synthetic Rubber) was added relative to 100 parts by weight of the copolymer. The solvent was removed from the copolymer solution by steam stripping, and the copolymer was dried by using hot rolls at 110°C. Meanwhile, a part of the copolymerized solution was extracted when the polymerized rate was 5%, and it was confirmed through analysis of the copolymer with NMR that tertiary amino groups were quantitatively introduced into initiating terminals of the copolymer. Example 2 Same sample as in Example 1 except that the extender oil in Example 1 was replaced by liquid rubber. Example 3 Same sample as in Example 1 except that 0.1 mmol of potassium dodecylbenzene sulfonate was used in combination with 3.4 mmol of n-butyllithium. Example 4 Same sample as in Example 1 except that the addition amount of lithium diethylamino ethoxide was changed to 3 mmol, that is, the molar ratio of the initiators [a] and [b] was changed from 1:0.5 to 1:0.88. Example 5 Same sample as in Example 1 except that the modifier in Example 1 was changed to diethyl adipate. Example 6 Same sample as in Example 1 except that the modifier in Example 1 was changed to 4,4'-bis(diethylamino)benzophenone. Example 7 Same sample as in Example 1 except that the modifier in Example 1 was changed to C-MD1. Examples 8 and 9 and Comparative Example 4 Same samples as in Example 7 except that the contents of vinyl bonds and bound styrene in Example 7 were varied. In Comparative Example 4, the content of styrene was 60% by weight, which falls outside the Claims of this application. Example 10 Same sample as in Example 7 except that the amount of initiator was increased, and neither extender oil nor liquid rubber were added. Example 11 Same sample as in Example 10 except that the content of bound styrene was 0%. Example 12 Same sample as in Example 10 except that the contents of vinyl bonds and bound styrene were varied. Example 13 Same sample as in Example 10 except that the addition amount of n-BuLi was increased to 9 mmol, that is, the molar ratio of the (a1) and butyl lithium was changed from 1:1 to 1:1.2. Example 14 Same sample as in Example 10 except that no additional butadiene was added before the addition of C-MD1. Example 15 Same sample as copolymerized in Example 10 except that diethylaminoethanol (3.7 mmol), dibutylamine (7.4 mmol) and n-BuLi (11.1 mmol) were directly added in this order to the reactor vessel in which the solvent, butadiene and styrene had been charged. A part of a polymerization solution was extracted when the conversion rate was 7%. It was confirmed through analysis of the copolymer with NMR that the tertiary amino groups were quantitatively introduced into initiating terminals of the copolymer. Example 16 Same sample as copolymerized in Example 10 except that dibutylamine (7.4 mmol), diethylaminoethanol (3.7 mmol) and n-BuLi (11.1 mmol) were directly added in this order to the reactor vessel in which the solvent, butadiene and styrene had been charged. A part of a polymerization solution was extracted when the conversion rate was 8%. It was confirmed through analysis of the copolymer with NMR that the tertiary amino groups were quantitatively introduced into initiating terminals of the copolymer. Example 17 Same sample as copolymerized in Example 10 except that the initial copolymerization temperature was changed to 40°C. Example 18 Into a 300 ml pressure-proof bottle were added 25 g cyclohexane, 3.7 mmol of lithium diethylaminoethoxide as [b2] component, 7.4 mmol of di-n-butylamine as [a1] component, and 7.4 mmol of n-butyllithium in this order, which were reacted at 27°C for 15 minutes. Then, 37 mmol of 1,3-butadiene was added to the reaction mixture, which were reacted for another 15 minutes to obtain a solution of an initiator. Next, as shown in Table 3, 2400 g of cyclohexane, 240 g of styrene, 324 g of 1,3-butadiene, and 1.68 g of tetrahydrofuran were charged into a reactor vessel having an inner volume of 5 liters purged by nitrogen. After the mixture was set to the initial polymerization temperature of 60°C, the entire initiator solution prepared above was added to the monomer solution to effect the copolymerization. When the conversion rate reached 100%, 36 g of 1,3-butadiene was added to convert terminals of the copolymer to butadienyllithium. Then, 3.4 mmol of tin dichlorodibutyl was added to the reaction mixture, which were reacted for another 10 minutes. Thereafter, 2,6-di-tertiary butyl-p-cresol was added to the copolymer solution, and the solvent was removed from the solution by steam stripping. Finally, the copolymer was dried by using hot rolls at 110°C. Example 19 Same sample as in Example 18 except that the amount of the initiator was increased, and the modifier was replaced by tin tetrachloride. Example 20 Same sample as copolymerized in Example 18 except that dibutylamine (7.4 mmol) and n-BuLi (7.4 mmol) were used as the [a1] component, and diethylaminoethanol (3.7 mmol) and n-BuLi (3.7 mmol) were used as the [b1] component. Example 21 Same sample as copolymerized in Example 20 except that the charged amounts of styrene, butadiene and tetrahydrofuran were varied. Example 22 Same sample as copolymerized in Example 20 except that the amount of tetrahydrofuran was varied. Example 23 Same sample as copolymerized in Example 18 except that lithium di-n-butylamide (7.4 mmol) was used as the [a2] component, and lithium diethylaminoethoxide (2.2 mmol) were used as the [b2] component. Example 24 Same sample as copolymerized in Example 18 except that lithium diethylamide (7.4 mmol) was used as the [a2] component, and tetrahydrofurfuryl alcohol (3.7 mmol) and n-BuLi (3.7 mmol) were used as the [b1] component. Example 25 Same sample as copolymerized in Example 18 except that N-methylbenzylamine (7.4 mmol) and n-BuLi (7.4 mmol) were used as the [a2] component, and lithium diethylaminoethoxide (3.7 mmol) was used as the [b2] component. Example 26 Same sample as copolymerized in Example 18 except that the charged amount of tetrahydrofuran was increased. Comparative Example 1 Same sample as in Example 1 except that the initiator was replaced by n-BuLi (3 mmol). Comparative Example 2 Same sample as in Example 11 except that the initiator was replaced by n-BuLi (7 mmol), the modifier was changed to silicon tetrachloride, and neither extender oil nor liquid rubber were used. Comparative Example 3 Same sample as in Example 12 except that the initiator was replaced by n-BuLi (6.3 mmol), the modifier was changed to silicon tetrachloride, and neither extender oil nor liquid rubber were used. Comparative Example 5 Same sample as copolymerized in Example 18 except that dibutylamine (9.1 mmol) and n-BuLi (9.1 mmol) as the [a1] component and no [b] component were used as the initiator. As compared with Example 18, the rate of copolymerization and the coupling efficiency were both reduced. Comparative Example 6 Same sample as copolymerized in Example 18 except that n-butyllithium was used alone as the initiator. Comparative Example 7 Copolymerization was carried out under the same conditions as in Example 18 except that N-methylaniline (7.4 mmol) was used as the secondary amine compound in the (a1) component, but no polymer or copolymer was produced. Comparative Example 8 Same sample as copolymerized in Example 18 except that the dibutylamine (7.4 mmol) and n-BuLi (7.4 mmol) were used as the [a1] component, and lithium tertiary butoxide (3.7 mmol) was used as the [b2] component. Comparative Example 9 A copolymer having a high content of bound styrene was obtained in the same manner as in Example 18 except that the charged amounts of styrene and butadiene were changed. Polymerization conditions and molecular characteristics of the copolymers obtained in Examples 1 through 17 and Comparative Examples 1-4 are shown in Table 2, and those of Examples 18-26 and Comparative Examples 5 through 9 are shown in Table 3. Examples 27 through 34 and Comparative Examples 10 and 11 A vulcanizate was produced from a sample with an extender oil or liquid rubber according to a compounding recipe B in table 1 (for high performance tire), and physical properties thereof were evaluated. The polymer used in the evaluations as well as the evaluated results of the physical properties are shown in Table 4. Physical values of tan δ at 0°C, tan δ at 50°C, Lambourn abrasion, and dry skid are given by index by taking those of Comparative Example 11 as 100. Example 30 was inferior to the other samples in terms of processability. Examples 35 and 36 and Comparative Example 12 A vulcanizate was produced from a styrene-butadiene copolymer added with neither extender oil nor liquid rubber according to a compounding recipe A in Table 1 (for low fuel consumption tire), and physical properties thereof were evaluated. The polymer used in the evaluations as well as the evaluated results of the physical properties are shown in Table 4. Physical values of tan δ at 0°C, tan δ at 50°C, Lambourn abrasion amount, and dry skid are given by index by taking those of Comparative Example 12 as 100. Example 37 and Comparative Examples 13 and 14 A vulcanizate was produced from a polybutadiene polymer added with neither extender oil nor liquid rubber according to a compounding recipe C in Table 1 (for large size tire), and physical properties thereof were evaluated. Physical values of tan δ at 0°C, tan δ at 50°C, Lambourn abrasion, and dry skid are given by index by taking those of Comparative Example 13 as 100. The polymer used and the evaluated results of the physical properties are shown in Table 4. High cis-polybutadiene (BROl manufactured by Japan Synthetic Rubber Co., Ltd.) was also evaluated as Comparative Example 14. Examples 38-46 and Comparative Examples 15-18 A vulcanizate was produced according to a compounding recipe A in Table 1 (for large size tire), and physical properties thereof were evaluated. Physical values of tan δ at 0°C, tan δ at 50°C, Lambourn abrasion, and dry skid are given by index by taking those of Comparative Example 15 as 100. The polymer used in the evaluations as well as the evaluated results of the physical properties are shown in Table 5. The following are seen from Tables 2 through 5. (i) When comparison was made regarding the polymerizing time between Example 1 and Comparative Example 1 and between Example 18 and Comparative Examples 5 and 8, it is seen that the polymerizing time was shortened to the same level in the case of using conventional organic lithium compounds when the particular lithium alkoxide in the present invention was added to lithium amide. Further, the reactivity between the modifier and polymer terminals can be greatly enhanced. (ii) When comparison is made between Example 1 and Examples 15 and 16, it is seen that the initiator used in the present invention enables the intended polymer or copolymer to be produced in a shorter time without changing the modifying reactivity. (iii) As to Examples 27 through 34 and Comparative Examples 10 and 11 for the evaluation of high performance tires, dry skid resistance and tan δ at 0°C of the rubber composition in Example 32 having high vinyl content and high bound styrene content can be improved, while the other physical properties are being maintained at the same levels. The rubber composition in Example 33 having a medium content of vinyl bonds has the best tan δ at 50°C and better abrasion resistance. The rubber composition in Example 31 having a low vinyl content has the best tensile strength and good abrasion resistance. When liquid rubber is added instead of an extender oil, tensile strength, abrasion resistance and dry skid resistance can be further improved (Example 28). (iv) When evaluation is effected between Examples 35 and 36 and Comparative Example 12 or between Examples 38 through 46 and Comparative Examples 15 through 18 for the evaluation of low fuel consumption tires, functional groups can be effectively introduced into both opposite terminals of molecular chains and the physical properties can be improved. In Examples 35 and 42, tan δ at 50°C is largely improved, and various physical properties can be well balanced in Example 36. In addition, tan δ at 50°C and abrasion resistance are largely improved in Example 38. (v) When comparison is made between Example 37 and Comparative Examples 13 and 14 for the evaluation of large size tires, it is seen that tan δ at 50°C and abrasion resistance was improved by effectively introducing functional groups at both opposite terminals of molecular chains, which gave even better results than those given by a high-cis polybutadiene which has been considered to be optimum in the conventional large size tires. As described above, according to the present invention, the polymerization or copolymerization reaction rapidly proceeds by using an initiator which is the reaction product between the specific alcohol and the organic lithium compound and/or the specific lithium alkoxide compound together with the reaction product between the secondary amine compound and the organic lithium compound and/or the lithium amide compound. Further, a random copolymer of the conjugated diolefin and aromatic vinyl compound, which is effectively modified or coupled with an organic compound containing a hetero atom, a tin compound and/or a silicon compound, can be produced. The rubber composition containing the above polymer or copolymer has excellent tensile strength, abrasion resistance, rolling resistance and steering stability, and may be suitably used as tire treads which are not limited to specific uses but used over a wide range including high performance tires, low fuel consumption tires and large size tires. Recipe A B C Natural rubber 30 0 50 (S) BR 70 100 50 High aromatic extender oil 0 7.5 0 Carbon black 50 75 50 Stearic acid 2 2 2 Zinc oxide 3 3 3 Antioxidant 1 0 1 0.8 0 0.8 Vulcanization accelerator 0.6 0 0.6 DM 1.2 1 1.2 0 0.5 0 Sulfur 1.5 2 1.5 Polymer No. Recipe Tensile strength (kgf/cm 2 ) Tan δ 0°C Tan δ 50°C Lambourn abrasion Dry skid Example 27 A B 220 104 103 135 105 Example 28 B B 240 107 108 169 120 Example 29 E B 216 102 105 129 107 Example 30 F B 234 101 109 134 106 Example 31 G B 225 107 102 140 106 Example 32 H B 190 128 100 100 140 Example 33 I B 215 100 113 125 100 Example 34 C B 210 100 101 120 115 Comparative Example 10 U B 207 110 74 80 110 Comparative Example 11 R B 185 100 100 100 100 Example 35 L A 270 102 158 140 100 Example 36 J A 297 110 120 146 103 Comparative Example 12 T A 250 100 100 100 100 Example 37 K C 278 100 126 119 101 Comparative Example 13 S C 276 100 100 100 100 Comparative Example 14 C 268 95 104 110 95 Polymer No. Recipe Tensile strength (kgf/cm 2 ) Tan δ 0°C Tan δ 50°C Lambourn abrasion Example 38 V A 298 105 121 127 Example 39 W A 288 103 110 124 Example 40 X A 291 103 118 125 Example 41 Y A 284 105 114 118 Example 42 Z A 281 115 125 119 Example 43 AA A 263 106 112 116 Example 44 AB A 282 105 107 121 Example 45 AC A 257 102 103 109 Example 46 AD A 254 135 104 107 Comparative Example 15 AE A 224 100 100 100 Comparative Example 16 AF A 251 100 101 97 Comparative Example 17 AH A 238 102 93 83 Comparative Example 18 AI A 255 130 83 81

Claims: A process for producing a conjugated diolefin polymer or copolymer, comprising the step of polymerizing 55-100% by weight of a conjugated diolefin with 0-45% by weight of an aromatic vinyl compound as monomers by using initiators [a1] and/or [a2] as well as initiators [b1] and/or [b2] in a hydrocarbon as a solvent, in the presence of an ether compound or a tertiary amine if necessary, wherein [a1] is a reaction product between at least one secondary amine compound (A) selected from compounds represented by the following formulae (a1-1), (a1-2) and (a1-3) and an organic lithium compound, a molar ratio between said at least one secondary amine compound (A) and said organic lithium compound being 1:0.2-5; (a1-1) is in which R 1 and R 2 are the same or different, and denote a group selected from H- or an alkyl group having 1-20 carbon atoms or a aryl group having 6-20 carbon atoms; (a1-2) is in which R 3 and R 4 are the same or different and denote an alkylene group having 1-3 carbon atoms, X is a group selected from -CH 2 -, -O- or -NH-, R 5 is H- or an alkyl group having 1-5 carbon atoms, and k is an integer of 1-4; (a1-3) is 5-benzyloxyindole, 3-azaspiro[5,5]undecane, 3-azabicyclo[3,2,2]nonane, and carbazole; [a2] is a lithium amide compound obtained by substituting Li for H in a >NH group of said secondary amine compound (A); [b1] is a reaction product between at least one alcohol (B) selected from compounds represented by the following formulae (b1-1), (b1-2), (b1-3), (b1-4) and (b1-5) and an organic lithium compound, a molar ratio between said at least one alcohol (B) and said organic lithium compound being 1:0.8-5; (b1-1) is in which R 6 , R 7 , and R 8 are the same or different, and denote H- or an alkyl group having 1-5 carbon atoms, and m is an integer of 1-3; (b1-2) is in which R 9 , R 10 , R 11 , R 12 , and R 13 are the same or different, and denote H- or an alkyl group having 1-5 carbon atoms, and n is an integer of 1-3; (b1-3) is R 14 p N((CH 2 ) q -OH] 3-p in which R 14 is an alkyl group having 1-20 carbon atoms or an aryl group having 6-20 carbon atoms, p is an integer of 0-2, and q is an integer of 1-3; (b1-4) is in which R 15 and R 16 are the same or different, and denote an alkylene group having 1-3 carbon atoms, Y is a group selected from -CH 2 -, -O-, -NH- and =N-(CH 2 ) s OH, r is an integer of 1-3, and s is an integer of 1-3; (b1-5) is in which R 17 and R 18 are the same or different, and denote H- or an alkylene group having 1-5 carbon atoms, and t is an integer of 1-3: [b2] is a lithium alkoxide compound obtained by substituting Li for H of an -OH in the alcohol (B); and wherein the content of vinyl bonds in the conjugated diolefin portion of the said polymer or copolymer is 15-90%. A process as claimed in claim 1, characterized by further comprising the step of, after the polymerization, modifying or coupling active terminals of polymer or copolymer with use of one or more compounds, as a modifier, selected from the following compounds, within a time period during which said active terminals of the polymer or copolymer remain: "a 0 " an isocyanate compound and/or an isothiocyanate compound "b 0 " a derivative of an isocyanuric acid and/or a thiocarbonyl-containing compound having a chemical structure corresponding to that of said isocyanuric acid derivative "c 0 " a urea compound "d 0 " an amide compound and/or an imide compound "e 0 " an N-alkyl-substituted oxazolidinon compound "f 0 " a pyridyl-substituted ketone compound and/or a pyridyl-substituted vinyl compound "g 0 " a lactam compound "h 0 " a silicon compound "i 0 " an ester compound "j 0 " a ketone compound "k 0 " a tin compound. A process as claimed in claim 2, characterized in that, before said modifier is added, 0.5-500 mol of 1,3-butadiene per 1 gram equivalent of lithium atom is added, and then the polymerization or copolymerization is further effected. A process as claimed in claim 2 or 3, characterized in that a molar ratio between said lithium compound of said [a1] or said lithium amide compound of said [a2] and said organic lithium compound of said [b1] or said lithium alkoxide compound of said [b2] is 1:0.01-2.0. A process as claimed in any of claims 2 to 4, characterized in that said [a1] is a reaction product between the secondary amine compound of the formula (a1-1) and said organic lithium compound, and said [a2] is a lithium amide compound obtained by substituting Li for H in -NH groups of the compound of said (a1-1). A process as claimed in any of claims 2 to 4, characterized in that said [a1] is a reaction product between di-n-butylamine and said organic lithium compound, and [a2] is lithium di-n-butyl amide. A process as claimed in any of claims 2 to 6, characterized in that said [b1] is a reaction product between the compound of said (b1-1) and/or the compound of said (b1-3) and said organic lithium compound, and said [b2] is a lithium alkoxide compound obtained by substituting Li for H in -OH groups of the compound of said (b1-1) and/or the compound of said (b1-3). A process as claimed in any of claims 2 to 6, characterized in that said [b1] is a reaction product between N,N-diethyl ethanolamine and/or tetrahydrofurfuryl alcohol and said organic lithium compound, and [b2] is N,N-diethylamino lithium ethoxide and/or tetrahydrofurfuryl lithium alkoxide. A process as claimed in any of claims 2 to 8, characterized in that said organic lithium compound is an alkyl lithium having 3-10 carbon atoms. A process as claimed in any of claims 2 to 9, characterized in that said hydrocarbon solvent is a cycloaliphatic hydrocarbon and/or an aliphatic hydrocarbon having 3-10 carbon atoms. A process as claimed in any of claims 2 to 10, characterized in that said conjugated diolefin is 1,3-butadiene and/or isoprene, and said aromatic vinyl compound is styrene. A process as claimed in any of claims 2 to 11, characterized in that said modifier is at least one compound selected from the isocyanate compound (a 0 ), the silicon compound (h 0 ) and the tin compound (k 0 ). A process as claimed in any of claims 2 to 11, characterized in that said modifier is at least one tin compound (k 0 ) in an amount of 0.05-5 gram equivalents per one gram equivalent of lithium atoms. A process as claimed in any of claims 2 to 13, characterized in that a rate of the modified or coupled polymer or copolymer to the entire polymer or copolymer is not less than 20% by weight based on the total polymer or the diolefin portion of said copolymer. A process as claimed in any of claims 2 to 14, characterized in that a content of vinyl groups in said diolefin polymer or copolymer is 15-40% by weight based on the total polymer or the diolefin portion of said copolymer. A process as claimed in claim 2, characterized in that the polymerization is effected by using, as the initiator, said [a1] being a reaction product between di-n-butyl amine and the organic lithium compound and/or [a2] being lithium di-n-butylamide and said [b1] being a reaction product between N,N diethylethanolamine and/or tetrahydrofurfuryl alcohol and the organic lithium compound and/or [b2] being N,N-diethylaminolithium ethoxide and/or tetrahydrofurfuryl lithium alkoxide; further polymerization is effected after 0.5-500 mol of 1,3-butadiene is added to the resulting polymer or copolymer per 1 gram equivalent of lithium; and the resulting polymer or copolymer is modified or coupled by adding at least one modifier selected from polymeric type diphenylmethane diisocyanate, dimethyl adipate, 4,4'-bis (dimethylamino) benzophenon, tin tetrachloride, silicon tetrachloride, and tin dichlorodibutyl, thereby making the rate of the modified or coupled polymer or copolymer not less than 20% by weight relative to the entire polymer or copolymer. A rubber composition containing not less than 30% by weight of a diolefin polymer or copolymer with respect to an entire rubber component, said diolefin polymer or copolymer being obtained by the following steps: (1) polymerizing 55-100% by weight of a conjugated diolefin with 0-45% by weight of an aromatic vinyl compound as monomers by using initiators [a1] and/or [a2] as well as initiators [b1] and/or [b2], wherein each of [a1], [a2], [b1] and [b2] is as defined in claim 1; (2) after the polymerization, modifying or coupling polymerization- or copolymerization-active terminals with use of one or more compounds, as a modifier, selected from compounds (a 0 ) through (k 0 ), within a time period during which said active terminals remain, wherein each of said compounds (a 0 ) through (k 0 ) is as defined in claim 2. A rubber composition as claimed in claim 17, characterized by comprising the steps of: (1) copolymerizing 55-90% by weight of said conjugated olefin and 45-10% by weight of said aromatic vinyl compound as the monomers; and (2) after the polymerization, modifying or coupling active terminals of the resulting polymer with use of one or more compounds, as a modifier, selected from said compounds (a 0 ), (h 0 ) and (k 0 ), within a time period during which said active terminals remain.

Inventors: HAMADA TATSURO, HATTORI IWAKAZU, YAMAKAWA YOSHITAKA, YASUDA KYOUYUU, YOKOYAMA HIDEAKI, HAMADA, TATSURO, HATTORI, IWAKAZU, YAMAKAWA, YOSHITAKA, YASUDA, KYOUYUU, YOKOYAMA, HIDEAKI, HAMADA, TATSURO, C/O BRIDGESTONE CORPORATION, HATTORI, IWAKAZU, C/O JAPAN SYNTHETIC RUBBER CO., YAMAKAWA, YOSHITAKA, C/O JAPAN SYNTHETIC, YASUDA, KYOUYUU, C/O JAPAN SYNTHETIC RUBBER CO., YOKOYAMA, HIDEAKI, C/O BRIDGESTONE CORPORATION
Applicants: BRIDGESTONE CORP, JAPAN SYNTHETIC RUBBER CO LTD, BRIDGESTONE CORPORATION, JAPAN SYNTHETIC RUBBER CO., LTD.
Application year: 1994
Main classification: C08F36
IPC codes: C08F4, C08F36